In pneumatic tires, cavity resonance caused by the vibration of air with which the tire is inflated is one cause of noise generation. When a tire is rolled, uneven road surfaces cause a tread portion to vibrate. The vibrations of the tread portion cause the air inside the tire to vibrate, which generates the cavity resonance.
In order to reduce noise caused by this cavity resonance, a configuration has been proposed wherein a sound-absorbing member is disposed inside a space formed between a tire and the rim of a wheel. More specifically, a belt-shaped sound-absorbing member is bonded to a region on the tire inner surface corresponding to the tread portion (see Japanese Unexamined Patent Application Publication Nos. 2002-67608A and 2005-138760A, for example).
However, when the belt-shaped sound-absorbing member is bonded to the region on the tire inner surface corresponding to the tread portion, heat is generated in the sound-absorbing member and the adhesive layer thereof when the pneumatic tire travels. As a result, softening or degradation occurs in the adhesive layer provided to fix the sound-absorbing member. Then, when the softening or the degradation occurs in the adhesive layer, there arises a problem in which the sound-absorbing member tends to be easily separated from the tire inner surface.